运行报错呀 [ERROR]-[Thread: localhost-startStop-1]-[com.jfinal.core.Config.startPlugins()]: Plugin start error: com.demo.activiti.ActivitiPlugins. nulljava.lang.NullPointerException at org.activiti.engine.impl.db.DbSqlSession.dbSchemaUpdate(DbSqlSession.java:993) at org.activiti.engine.impl.db.DbSqlSession.performSchemaOperationsProcessEngineBuild(DbSqlSession.java:1385) at org.activiti.engine.impl.SchemaOperationsProcessEngineBuild.execute(SchemaOperationsProcessEngineBuild.java:25) at org.activiti.engine.impl.interceptor.CommandInvoker.execute(CommandInvoker.java:24) at org.activiti.engine.impl.interceptor.CommandContextInterceptor.execute(CommandContextInterceptor.java:57) at org.activiti.engine.impl.interceptor.LogInterceptor.execute(LogInterceptor.java:31) at org.activiti.engine.impl.cfg.CommandExecutorImpl.execute(CommandExecutorImpl.java:40) at org.activiti.engine.impl.ProcessEngineImpl.(ProcessEngineImpl.java:77) at org.activiti.engine.impl.cfg.ProcessEngineConfigurationImpl.buildProcessEngine(ProcessEngineConfigurationImpl.java:413) at com.demo.activiti.ActivitiPlugins.buildProcessEngine(ActivitiPlugins.java:46) at com.demo.activiti.ActivitiPlugins.start(ActivitiPlugins.java:26)

Failed to execute goal org.apache.maven.plugins:maven-compiler-plugin:2.3.2:compile (default-compile) on project weixin_guide: Compilation failure[ERROR] Unable to locate the Javac Compiler in:[ERROR] C:\Program Files\Java\jre1.8.0_131\..\lib\tools.jar[ERROR] Please ensure you are using JDK 1.4 or above and[ERROR] not a JRE (the com.sun.tools.javac.Main class is required).[ERROR] In most cases you can change the location of your Java[ERROR] installation by setting the JAVA_HOME environment variable.